通过TurtleBot学navigation与ROS的笔记

TurtleBot运行的几条关键语句

#启动仿真环境 roslaunch turtlebot_gazebo tuetlebot_world.launch #键盘控制 roslaunch turtlebot_teleop keyboard_teleop.launch #rviz roslaunch turtlebot_rviz_launchers view_robot.launch

测试Kinect（仿真环境下不需要Kinnect，日后再补充）

http://learn.turtlebot.com/2015/02/01/8/

echo $TURTLEBOT_3D_SENSOR # Output: kinect

如果输出不是kinect，则需要更改该变量

echo "export TURTLEBOT_3D_SENSOR=kinect" >> .bashrc

显示深度图和RGB图

rosrun image_view image_view image:=/camera/depth/image_raw

此处的:=意为覆盖赋值。其他的还有 ?=若左边变量未被赋值则赋值 +=在左边变量后面加上新字符串

简单例子 Draw a square

#!/usr/bin/env python ''' Copyright (c) 2015, Mark Silliman All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. ''' # An example of TurtleBot 2 drawing a 0.4 meter square. # Written for indigo import rospy from geometry_msgs.msg import Twist from math import radians class DrawASquare(): def __init__(self): # initiliaze rospy.init_node('drawasquare', anonymous=False) # What to do you ctrl + c rospy.on_shutdown(self.shutdown) self.cmd_vel = rospy.Publisher('cmd_vel_mux/input/navi', Twist, queue_size=10) # 5 HZ r = rospy.Rate(5); # create two different Twist() variables. One for moving forward. One for turning 45 degrees. # let's go forward at 0.2 m/s move_cmd = Twist() move_cmd.linear.x = 0.2 # by default angular.z is 0 so setting this isn't required #let's turn at 45 deg/s turn_cmd = Twist() turn_cmd.linear.x = 0 turn_cmd.angular.z = radians(45); #45 deg/s in radians/s #two keep drawing squares. Go forward for 2 seconds (10 x 5 HZ) then turn for 2 second count = 0 while not rospy.is_shutdown(): # go forward 0.4 m (2 seconds * 0.2 m / seconds) rospy.loginfo("Going Straight") for x in range(0,10): self.cmd_vel.publish(move_cmd) r.sleep() # turn 90 degrees rospy.loginfo("Turning") for x in range(0,10): self.cmd_vel.publish(turn_cmd) r.sleep() count = count + 1 if(count == 4): count = 0 if(count == 0): rospy.loginfo("TurtleBot should be close to the original starting position (but it's probably way off)") def shutdown(self): # stop turtlebot rospy.loginfo("Stop Drawing Squares") self.cmd_vel.publish(Twist()) rospy.sleep(1) if __name__ == '__main__': try: DrawASquare() except: rospy.loginfo("node terminated.")

仿真环境下可以实现较为精确的速度控制。此例程中需要注意的

#执行一次r.sleep，ROS会控制睡眠时间为上次调用到这次调用刚好为0.2s。 r = rospy.Rate(5); r.sleep() # What to do you ctrl + c rospy.on_shutdown(self.shutdown)

创建地图

http://learn.turtlebot.com/2015/02/03/8/

roslaunch turtlebot_gazebo turtlebot_world.launch roslaunch turtlebot_gazebo gmapping_demo.launch roslaunch turtlebot_rviz_launchers view_navigation.launch